How do you find the true shape of a section?

How do you find the true shape of a section?

To find the true shape of a section, it must be projected on a plane parallel to the section plane. For polyhedra, the true shape of the section depends on the number of POIs. The shape of the section will be a polygon of the sides equal to the number of POIs.

What is true shape in engineering drawing?

Sections : The projection of the section on the reference plane to which the section plane is perpendicular will be straight line coinciding with the trace of the section plane on it. True shape of the section : Projection of the section on a plane parallel to the section plane will show the true shape of the section.

How do you represent a sectioned surface on a drawing?

A sectioned surface is represented by drawing thick lines at angle 45° to the drawing on the sectioned surface, (this is done with the use of a tee square and 45° set square when drawn on a t board).

What is true shape of section in section of solids?

True shape of a section. The projection of a section on a plane parallel to the section plane will show the true shape of the section. ➢ When the section plane is parallel the H.P. or the ground, the true shape of the section will be seen in sectional top view.

What is section of solid?

Imagine a solid to have been cut by a straight plane, called a cutting plane (CP). The new surface created by cutting the object is called a section.

How do you find true lengths?

To find the true length of a line you must take a view parallel to the line; in other words, if a line is a parallel to the folding line in one view, it is shown in true length in the adjacent view.

What is true length in engineering drawing?

In geometry, true length is any distance between points that is not foreshortened by the view type. In a three-dimensional Euclidean space, lines with true length are parallel to the projection plane.

Why sectioning is done?

Sections are used to clarify the interior construction of a part that cannot be clearly described by hidden lines in exterior views. By taking an imaginary cut through the object and removing a portion, the inside features may be seen more clearly.

How are section lines used in engineering drawing?

Each cutting plane will create a section view, and each section view is drawn as if the other cutting plane did not exist. Section Line Practices Section lines or cross-hatch lines are added to a section view to indicate the surfaces that are cut by the imaginary cutting plane.

How are traditional section views based on imaginary cutting plane?

•Traditional section views are based on the use of an imaginary cutting plane that cuts through the object to reveal interior features.

What should the spacing be in a engineering drawing?

As a general rule, use 3mm spacing. Section lines are drawn as thin (.35 mm) black lines, using an H or 2H pencil. The section lines should be evenly spaced and of equal thickness, and should be thinner than visible lines Also, do not run sectionlines beyond the visible outlines or stop them too short

What do the diagonal lines on a section drawing mean?

The diagonal lines on the section drawing are used to indicate the area that has been theoretically cut. These lines are called section lining or cross-hatching. The lines are thin and are usually drawn at a 45-degree angle to the major outline of the object. The spacing between lines should be uniform.